Upgrading a network device—e.g., a router, switch, bridge, server, and the like—may require that the device stop transmitting, receiving, or forwarding data packets. In turn, this outage may cause other network devices (e.g., routers, switches, or client devices) coupled to the device being upgraded to not receive data packets. For example, if an end device relies on a router to access an external network (e.g., the Internet) but the router is offline while an upgrade is being performed, the end device may be unable to transmit or receive data traffic via the external network.
Often, a network administrator may choose to upgrade network devices when data throughput is the lowest, thereby minimizing the service interruption. Alternatively, different upgrade techniques may allow a network device to be upgraded while still permitting data plane traffic to flow through the device. However, these techniques apply to a limited number of network device architectures and/or software updates. For example, if the upgrade includes updating hardware responsible for forwarding data traffic, the network device may not be able to perform the upgrade without a service interruption.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation.